NASA still hasn't learned

I see that NASA is going to try to launch Atlantis on Friday morning over the objections of their own safety teams and the manufacturer of a faulty fuel cell. Launch regulations are supposed to prohibit launching without all three fuel cells operational. Hey, NASA--remember the Challenger? Geesh, what's NASA's motto, "Fool me once, shame on you; fool me twice, want a job at NASA?"

I see they've also got a faulty fuel level sensor--the same problem they've had in the past and chose to ignore. From Space.com:

NASA Eyes Fuel Tank Sensor Glitch for Shuttle Launch
8 September 2006 5:23 a.m. EDT

CAPE CANAVERAL, Fla. – NASA engineers have spotted a problem with one of four engine cutoff sensors inside the liquid hydrogen portion of the space shuttle Atlantis’ external tank.

NASA spokesperson Bruce Buckingham said shuttle officials agreed to press forward with fueling Atlantis for today’s planned 11:40:32 a.m. EDT (1540:32 GMT) launch as troubleshooting efforts continue.

Engine cutoff sensors (ECO) are used as a sort of shuttle fuel gauge to measure the amount of propellant remaining inside Atlantis’ external tank during flight. They are designed to automatically shut down a shuttle’s three main engines if the level of liquid hydrogen or liquid oxygen is close to running out, since firing the engines without propellant could cause serious damage to the orbiter.

Buckingham said the sensor in question is ECO 3 in Atlantis’ liquid hydrogen tank.

The sensor is reading ‘wet’ – meaning it is submerged in liquid hydrogen – instead of ‘dry’ – which flight controllers direct the sensor to indicate in a standard preflight check.

NASA has had seen ECO glitches in the past – most recently with the STS-114 mission in 2005, when an ECO sensor failed during a routine tanking test to ensure it was operating properly.

This is shaping up to be a dangerous flight.